Code call interrupter circuit



Aug. 4, 1942. B. A. WALLACE CODE CALL INTERRUPTER CIRCUIT Filed Nov. 18, 1940 2 sheets-Sheet 1 U8- 4, 1942- B. A. vWALLACE 2,292,183

CODE CALL INTERRUPTER CIRCUIT Filed Nov.. 18, 1940 2 Sheets-Sheet 2 i i TFH-H,

EeWHZ/Z/Z/ace. 2 Ey Patented Aug. 4, 1942 CODE CALL IN TERRUPTER CIRCUIT- Bert A. Wallace, Chicago, Ill., assignor to Kellogg Switchboard and Supply Company, Chicago, Ill., a corporation of Illinois Application November 18, 1940, Serial No. 366,041

5 Claims.

This invention relates to telephone systems, and more particularly to a system employing machine switching apparatus, wherein any subscriber may set up a code call, wait for an answer from the called party, and hold a conversation.

One object of this invention is to provide a code call system whereby any subscriber can initiate a code call signal. Another object is to provide means whereby a code call signal can be selectively initiated. A further object is to provide a code call system wherein each code call sequence is always completed.

One feature of this invention allows a subscriber to set up a code call line connection by dialing an assigned number. Another feature permits code call selection by the dialing of an additional digit. Another feature precludes interference with the original code call by the accidental or subsequent dialing of other digits.

Another feature of this system provides for the complete sounding of a code call, one or more times, even though the originating party has abandoned the call, or the called party has answered in the middle of the call. Another feature permits any telephone in the exchange to be used by dialing the number assigned for the code call purpose. Another feature permits stopping the code call signal after the called party has answered, but only `after completion of a code call sequence. Another feature sets up a conversational circuit between a code call line and a code answer line.

A further feature starts the code interrupter after completion of the code selecting digit. A further feature of the device resides in the provision of a power contacter to close battery to multiple code signal apparatus.

Other objects, features, and advantages of this invention will appear from the following description, taken in connection with the accompanying drawings.

In the drawings, Figs. 1 and 2 are to be taken together' to show a circuit diagram of a system having features of the present invention. Fig. 1 is to be placed on the left of Fig. 2. The various circuits in each ligure are correspondingly marked and completed in the adjacent figure.

Considering the drawings in greater detail, at

the upper left hand portion of Fig. 1 is shown a series of multipled connector switches A for connecting together the link used by a calling subscriber station and the code call system or circuit. The multiple at A is connected to code call line circuits TI, RI, SI; T2, R2, S2; etc.; and also to the preliminary pulse selector relays B. The code call interrupter circuit C (on both Figs. 1 and 2) includes the chain of relays I to ZI, inclusive, and 22 the call signal power contactor. Each set of tip and ring conductors TI and RI, etc., go to the conference line circuit D, while the lines T and R provide for the answering circuit. The chain of relays E provide for the nal pulses of the code call actually selected.

The transmitter hundreds and tens impulses from a calling subscriber station selects one of the circuits CLI, CL2, CL3 and CL4 depending upon the number dialed and then operates and locks up the respective preliminary pulse selector 25, 26, 2l or 28 of the selected circuit. The operation of any one of these pulse selectors in turn locks up relay 24 and places ground upon the sleeve circuit of all of the nonselected lines. The further dialing of the last or units digit sets up the code selector relays I6! to IIE. Upon completion of the dialed digit, the chain C is then placed in operation thereby ringing the code call until the called party answers or the calling party abandons the call. When the call is answered from any one of the subscriber stations, the conversational circuit is completed by relay I I5. This in turn will prepare a circuit for relay II5, which latter only operates upon the operation of relay I, and locks through relay 8. This operation of relay I I5 removes battery from the chain E and releases any of the relays of that group which were locked up. It also trips relay H4; relays I9, 20 and 2|; Il or I8; and I. The foregoing is a very brief description of the operation.

The circuits herein described can, for example, he used for any one of the forty diierent code calls, using different arrangements or combinations of four preliminary pulses and ten selector or nal pulses in setting up the actual code call signal. For example, code call line one (CLI) is used for all calls using a single preliminary pulse and either none or any combination of nine nal pulses to make a complete code call signal. For example, if the dialing numbers 910 to 919, inclusive, are assigned to circuit CLI, the following would illustrate one arrangement or series of ten code calls.

Sixteen relay step chain The calling party dials the number 949. The first two hundreds and tens digits 94- determine which one of the code call line circuits will be used. As assumed, it will select CL4 through the customary automatic relays, finders, selectors, links I or 2, and connectors 23 or 29 of the automatic telephone exchange. On the further assumption that this line circuit is idle, the hereinafter described operations will take place.

The connection will place ground on the sleeve circuit S4 to operate relay 28 by a circuit: grounded battery, winding 28, normal contact and armature 35 of relay 24, to ground on S4. Relay 28 operates and locks through its front contact and armature 3 I, to ground on sleeve S4. The operation of relay 28 in turn energizes relay 24 from ground; through contact and armature 32 of relay 28, conductor 33, winding 24, grounded battery. Armature 32 of relay 28 also places articial ground busy test upon each of the nonselected sleeves SI, S2 and S3 of the remaining code call circuits CLI, CL2 and CL3. This ground is from grounded conductor 33, to armature 34 and normal contact .of 2l, front contact and armature 35 of relay 24, to sleeve S3. Ground on S2 is from 33 to armature 35 and normal Contact of 26, front contact and armature 3l of 24 to S2. The ground on SI is from grounded conductor 33 to armature 38 and normal contact of 25, front contact and armature of 39 of 24 to sleeve. Every time a subscriber puts the codecall into operation, the unused circuits are given a busy test ground in the same manner. The operation of relay 24 also opens the circuits of relays 25, 25 and 2l at armatures 39, 3l and 35, respectively. The armatures 4! to 49, inclusive, are connected to ground at armature 50 and normal contact of relay 29 (which latter is slow to pick-up and slow to release), over conductors I and 52. rThe operation of relay 23 at its armatures v40 to 43, therefore, places a ground upon the lowermost front contact of each of relays 2, 3, 4 and 5 of chain C.

The seizing of CL4 also operates relay I II from the battery on the tip and ring conductors T4 and R4 as follows: T4, TI, repeating coil RCI, winding I Il, repeating coil RC2, RI, to R4. Relay ||8 (which latter is very slow to release) is in turn connected to ground and operated by relay II'I at the latters front contact and armature 53.

The subscriber now dials the neXt code selecting digit 1, 2, 3, 4, 5, 6, 7, 8, 9 or 0, causing the release of relay I I'I a number of times equal to the digit dialed. In this case, the digit is 9 and relay II'I is released nine times. Relay ||8 is'slow in releasing and holds over during the release of relay II'I. A ground pulse is connected at armature 53 and normal contact of relay II'I, through armature 54 and front contact of relay IIE, to armatures 55 and 55 of relay H4 at each release of relay I I'I..

The rst ground pulse through armature 55 and normal contact of relay 4 operates slow relay I I3 which holds over for all succeeding impulses of the digit dialed and then releases. The first ground pulse through armature 55 and normal contact of relay ||4 is carried to the armatures 5l and 58, respectively, of relays I II and I I2 and operates relay IDI. The latter is energized by a circuit through armature 5l and front contact of relay III, conductor 59, winding of relay Ill, through the series of upper, inner normal contacts of relays |92 to |09, the corresponding contact of relay I I Il, conductor 5U to grounded battery on armature 6| and normal contact of relay I I5. Relay II operates and locks, from this grounded battery through the armature 6| and normal Contact of relay ||5, conductor 63, the series of upper inner normal contacts on relays |Il2 to I i0, winding of relay IIlI, conductor 59, winding of I I I, conductor 62, armature 63 and front contact of III I, ground conductor 34. Relay III does not operate because its winding was vshunted by the first ground pulse, but it does operate at the end of this ground pulse when relay I I'I reoperates and removes the shunt ground off of armature 5l.

The second ground pulse, assuming that a higher digit than 1, viz., 9, is dialed, operates relay I 62. The circuit is now from the new ground on armature 55, through armature 58 and normal contact of relay ||2, conductor 65, winding of relay |52, front Contact and armature 66 of relay IIII, conductor 31, front contact and armature 58 of relay III, conductor 69, normal contact and armature 6| of relay I I 5 to grounded battery. Relay |52 operates and locks through the coil of relay I I2, but relay I I2 does not operate at this time because it was shunted by the operating ground pulse from armature 58. The locking circuit of relay I G2 is from grounded battery to armature 6| and normal contact of relay ||5, conductor 60, the upper inner series of normal contacts of relays |93 to IB, front contact and armature 68 of relay |62, winding of relay |02, conductor 55, winding ||2, armature B9 and front contact of relay |32, to grounded conductor 64. This operation of relay v||l2 in turn releases relays |0| and ||I by removing battery as a result of the opening of the upper inner normal contact of relay |32 by the operation of its armature 68. IThe reoperation of relay II'I ends the second ground pulse and removes the shunt ground from relay ||2, allowing the latter to operate and prepare a circuit for relay |03 by placing battery on armature 'II and front Contact of relay |32, through the engagement of armature 'I0 and front contact of relay I2.

L|03 in turn locks by circuit over its armature 13 and the winding of relay `I This circuit is as follows: grounded conductor 64, front contact and armature 13 of relay |03, conductor 62, Winding I I conductor 59, winding |03, armature 12 and front contact of |03, the inner upper normal f contacts of relays |04 to ||0,"conductor-60, normal contact and armature 6| of relay II5, grounded battery. The reoperation'of relay |I1 aga-in removesthe shunting ground from armature 51 of relay III and permits the latter relay toioperate from the locking circuit of-relay |03.

The fourth ground pulse operates relay |04 and locks `through relay I|2 which latter subsequently reoperates. Relay |04 releases relays I 03 and I I I. The circuits and mode of operation are similar to thatedescribed in connection with relay |02.

The fifth ground pulse operates relay |05, in turn releasing relays |04 and II2. After theremoval of the ground pulse, relay I I operates.

The sixth ground pulse operates relay |06 which in turn locks through the Winding of relay ||2 which latter is reoperated upon the removal of the ground pulse at relay 1. of relay |06 in turn releases relays |05 and'l I The seventh ground pulse operates relay |01 which in turn locks through the Winding ofrelay III which does not operate. The operation of relay |01 in turn releases relays |06 and II2. `Relay II-I subsequently operates.

The eighth ground pulse operates relay |08 which locks through the circuit of relay I'I2. The operation of relay |08 in `turn releases relays |01 and III. The reoperation of relay I|1 removes shunting ground and allows relay ||2 to operate through locking circuit of relay |08.

The ninth ground pulse operates relay |09, which latter locks through the Winding of .relay |08 and ||2. The reoperation of relay ||1 again removes the shunting ground and permits relay to operate over the locking circuit of relay -I09. The code call selector circuit E now hasits relays II`3, and |09 in actuated position.

The selection circuit B now has preliminary pulse relays 24 and `28 in actuated position with all of its other relays locked out of their normal circuits. The conversational line circuit D now has its relays l|1 and `|`|8 in actuated position. One or the other of the link `relays 23 and 29 will be in operated position depending upon the switchboard circuits. `In the description thus far, the operation of the code call apparatus has been setting up the particular code call desired. The

code call signal itself has not beengiven.

The means for actuating the signal `will now be described. The completion of the last ground pulse of the digit dialed, removes the ground from armature 56 of relay ||4 and in turn removes ground off of relay ||3. Although thislrelayis a slow relay, the continued absence of ground permits it to release. Relay I|| at its armature 14 and front Contact, places ground upon the inner lower contact of relay II3 so that'the release of the latters `armature 15 in turn places ground upon relay ||4. The latter operates -ts armatures and 55, thereby precluding any further stepping of the relay chain |0| to ||2, inclusive.

then

The operation The operation of relay |09 releases relays Cal If the relay kchain E had locked upon an even numberedrelay with the consequent operation of relay IIZ, theground for relay ||4 would then have been provided by the armature 82 and front contact oirelay -I I2.

The releaseof relay |I3, at its armature 15, provides a ground through armature 16 and normal contact of relay II5, and conductor 11, for relays I9 and 2|. This ground starts into operation, the code call interrupter starting relays to initiaterelay chain I to I0, inclusive. Relay i9 is slow to release and relay 20 is slow both on pick-up and release. The operation of these two relays, together, Vassures a slow sequential movement of the relay chain C and the consequent Yslow code call.

The ground on conductor 11 completes a circuit forrelay 2| to grounded battery. The relay operates and locks through the armatures of relays I||, I'I3 and II5. This ground also completes a circuit for relay I9 through armature 18 and normal Contact of relay 20. Relay I9, at its armature 19 and front contact, placed ground upon the winding of relay 20 causing the latter to operate. The operationof relay 20 at armature 50 removed the ground from conductor 5| and from Varmatures 40 to 49, inclusive, of the preliminary pulse relays, and more particularly 40 to 43,1inclusive, of relay 28; and placed ground upon the conductors and 8|.

Relay L'E in operating breaks the circuit for relay I9, at its armature 18 and normal contact. The release of relay I9 at its armature 19 and front contact, in turn removed ground from relay 420 to release the latter. The release of relay `20 in turn restores ground to conductor 5I, andalso atitsarmature 18 to relay I9. Relay I9 in turn reoperates and completes a circuit for the reoperation of relay 20.

Everytime that-relay'20 is energized, it will placeground upon conductors 80 and 8|. Relay 2| -at its armature 83 and front contact places battery on conductors 84 and B5. Upon each actuation of'relay 20, while relay 2| is energized, battery and ground, respectively, will be placed upon oneof the chain of relays I to I0 by con ductors-85 and 8|.

The operation of each of the chain of relays to will prepare a circuit for the next relay insequence and trip the locking circuit of the last'relay of the sequence. The odd numbered relays Willvlock up VVthrough the relay |1 and the even numbered relays will lock up through the winding or relay-I8. A more detailed explanation of this operation follows.

The operation kof relay `20 at its iront Contact and armature 50, places ground onconductor-Stl to armature 85 and normal contactlof relay I1, conduct-or 0|, winding of relay I, through the upper inner normal .seriesof contacts of relays `f2-to I6, inclusive, to conductor 05, conductor/84, iront contact and armature 83 of relay 2| to grounded battery. Relay I operates and locks through the winding of relay I1 over the following circuit: grounded battery, armature S3 and front contact of relayZI, conductor 84, conductor-05, series of upper inner normal contacts of relays 2 to I winding of relay I, con or 0|, winding of Il, conductor 81, armature 0S and front contact cl relay I to grounded conductor S9. Relay I1 was shunted by the initial operating ground pulse and did not operate, The release o'i relay 20 removes the shuntinU ground from relay I1 permitting the same to subsequently operate with the consequent opening at its armature 86 of the initial operating circuit for relay I. The operation of relay I1 at its armature 90 and front contact connects the grounded battery to armature 9| and front contact of relay I to preset the circuit for the operation of relay 2.

The release of relays I9 and 20 and the subsequent reoperation of relay 29 again places ground on conductor 80 to operate relay 2 by means of the following circuit: ground, armature 50 and front contact of relay 20, conductor 80, armature 92 and normal contact of relay I8, conductor 93, winding of relay 2, front contact and armature 9| of relay I, conductor 94, front contact and armature 99 of relay I'I, conductor 84, front contact and armature 83 of relay 2|, to grounded battery, Relay 2 operates and locks through winding of relay I 8, which latter does not operate due to a shunting ground. Relay 2 locks over the following circuit: grounded battery, armature 83 and front contact of relay 2|, conductor 84, conductor 85, upper inner normal series of contacts, relays 3 to I6, front contact and armature 95 of relay 2, winding of relay 2, conductor 93, winding of relay I8, conductor 96, armature 9`| and front contact of relay 2 to grounded conductor 09. The operation of relay 2 releases I and I1 by the opening of the battery circuit by the operation of armature 95 at break-after-make contact of relay 2. Armature 98 of relay 2 prepares a circuit for relay 3. The release of armature 20 removes the shunting ground from relay I 8 and permits the latter to operate.

The circuit is now set for the first preliminary pulse of the code call signal which will be sounded upon the release of relay 20. The release of relay 20 at its armature 50 and normal ccntact, restores ground to the preliminary pulse relay armatures over conductors and 52. It also provides a ground from armature 43 and front contact of relay 28, front contact and armature 99 of relay 2, conductor |00, normal contact and armature I|9 of relay II3, conductor |20, to the winding of the code signal relay, to grounded battery. The code call signal relay 22 is energized, operating its armatures to complete a local circuit for the multipled code call signals throughout the particular store, factory, ofce or other installation, 'Ihe operation of relay will again remove the ground from conductor 5I thereby deenergizing relay 22. 'I'he next pulses to operate relay 22 will come from armature 42 of relay 28, and armature |22 of relay 3; or armature 4| of relay 28 and armature |23 of relay 4 and finally from armature 40 of relay 28 and armature |24 of relay 5.

Relays 2, 3, 4 and 5 of the Code call interrupter circuit C thereby provide for the preliminary pulses of the code call interrupter. Relay 6 does not have an armature controlling the code call interrupter. It therefore merely provides a means for continuing a sequence of relay operation.

The operation of relay 3 in turn releases relays 2 and I8, and then locks up through the winding of relay I'| which latter operates upon the release of relay 20. The operation of relay 3 prepares a circuit for relay 4. Relay 3 at its armature |22 completes a second preliminary pulse of the code call signal over the following circuit: ground to armature 50 and normal contact of relay 20, conductor 5|, conductor 52, armature 42 and front contact of relay 28, front contact and armature 22 of relay 3, conductor |00, normal contact and armature ||9 of relay ||3, conductor |20, winding of code call signal relay 22 to grounded battery.

The next ground pulse set up by relay 20. at its armature 50 and front Contact, operates relay 4 thereby releasing relays 3 and I'I, and locking up through relay I8. The release of relay 20 again places ground upon conductor 52 through armature 4| and front contact of relay 28 from front contact and armature 23 of relay 4, conductor |00, normal contact and armature |I9 of relay IIS, conductor |20, winding of relay 22 to grounded battery setting up the third preliminary pulse of the code call. The reoperation of relay 20 operates relay 5 releasing relays 4 and I8 and locking up through relay II which latter operates upon the release of relay 20. The release of relay 20 sets up the fourth and last Preliminary pulse of the code call from conductor 52, armature 40 and front contact of relay 28, front contact and armature |24 of relay 5, conductor |00, etc. This terminates the preliminary series of pulses or signals on the code call.

If the dialed code call circuit number is such as to Seize the line CLI instead of CL4, only one preliminary pulse would have been sounded and this by armature |24 of relay 5. In such a case, relays 2, 3 and 4 would have operated as part of the chain of relays C, but they would not complete a Circuit for the code call signal. In this instance, relay 25 Would have locked up instead of relay 28 and the circuit to the code call device would have been through armature |24 of relay '5 and armature 49 of relay 25.

Relay 6 operates and the code call skips one pulse due to the absence of the code call armature on relay 6.

The operation of relays to I5 in step by step sequence will follow in the same manner as described in connection with relays I to 6, each even numbered relay locking through relay I8 and each odd numbered relay locking through relay I1.

The operation of relay 'I at its armature |25 and front contact sets up the rst impulse of the nal portion of the selected code call signal. Relay |89 was locked up as a result of the selection so that nine code pulses will be given by the relays 'I to I5, inclusive. The rst pulse will be given after relay 'I has operated upon the release of relay 20. This circuit is as follows: ground, armature 50 and normal contact of relay 29, conductor 5|, front contact and armature I 25 of relay l, conductor |26, normal contact and outer lower armature |21 of relay 8 and series relays 9 to I5, inclusive, conductor |28 to front contact and armature |29 of relay |09 to normal contact and armature |39 of relay I I 0, conductor |80, normal contact and armature I|9 of relay H3, conductor |20, winding 22 to grounded battery. The operation of relays 8 to I5, inclusive, set up the additional pulses through the armature |29 of relay |09.

After the operation of relay I5 and the completion of the last code call pulse, the chain of relays I to I6 continues its sequential operation until stopped. Each time a sequence is completed, another code call is sounded. This continues until the code call is terminated by either an answer, or abandonment by the calling party.

The change-over from sounding of one sequence to another will be described. The operation of relay 20 places ground on relay I6 by the following circuit: ground, armature 50 and front contact of relay 28, conductor 80, armature 92 and normal contact of relay I8, conductor 93, the normal upper inner contact of relay conductor I3I, to winding of relay l5. Battery is supplied from grounded battery through armature 83 and front Contact of relay 2|, to conductor 84, armature 9|] and front contact of relay II, conductor 94, armature |32 and yfront contact of relay I5, to winding of relay I6. Relay IB operates and locks through its upper inner armature and the winding of relay I8 which latter does not operate until the release of relay 20. Relay I locks over the following circuit: grounded battery, armature 83 and front contact of relay 2|, conductor 84, conductor 85, front contact and armature |33 of relay I8, winding of relay I6, conductor I3I, normal contact of relay I, conductor 93, winding of relay I8, conductor 96, armature I'34 and front Contact of I6, to groundedconductor 89. Relay IB, in operation, releases relays I5 and I'I. The lowerrnost armature of relay I6 is not connected to the code call device so it does not set up a code pulse.

The re-operation of relay 2B operates relay I by the following circuit: grounded battery, armature 83 and front contact of relay 2|, conductor 84, armature and front contact of relay I8, conductor |35, armature |31 and front contact of relay I6, armature |38, winding of relay I, conductor 8|, armature 83 and normal contact of relay I1, conductor Ell, front contact and armature 58 of relay 2G, to ground. Relay I in operating trips I8 and I, and locks through winding of relay Il over the circuit: grounded conductor 89, front contact and armature 88 of relay I, conductor 8l, Winding of relay I'I, conductor 8|, winding of relay I, series of normal contacts of relays 2 to I5, conductor 85, conductor 84, armature 83 of 2|, to grounded battery. The sequence and code call will now be repeated.

Had the calling party dialed an assigned number 94D instead of 949, relays III) and |I2 would have locked up for the code selection in chain E. Since the pulse armature of relay I8 is not connected to the code call circuit, the call then sounded would only contain the four preliminary pulses:

When the called party hears the code call signal and dials the code call answering number from any telephone, to seize answering line ALI, relay IIB will be operated from tip and ring battery of the link used through repeating coils RC3 and RC4. This completes the conversational circuit. The code call signals can only be inuenced when relay I operates. This feature of the system provides for the complete sounding of a code call, to preclude the sounding of partial signals resulting in improper code calls.

The answering party can only control the code call signals to stop them by operating relay IIS just prior to the operation of relay I. Relay IIB will remain energized and as soon as relay I operates, a circuit will be completed for relay II5 as follows: grounded common 83, front contact and armature |40 of relay conductor I4I, front contact and armature |39 of relay I I5, conductor |42, normal contact |43 of relay II5, Winding of relay I I5 to grounded battery. Relay ||5 operates and locks over its make-beforebreak contact and armature |44, to ground through armature |45 and front contact of relay II8. It releases relays of the interrupter chain by removing ground at its armature 16, thereby releasing relays 2|, 'and I8 or 20 whichever is in at the moment. The release of relay 2| in turn releases relays I1 and I by removing battery.

Relay II5 in turn also releases relays III and |09 by removing battery at its armature 6 I Relay I|I in turn removes ground at armature I4 and releases relay I`I4.

A conversational circuit is available with relays 24, 28, I|5 to IIB, inclusive, energized. The code call device cannot be initiated during the conversation because of the artificial busy test on lines CLI, CL2 and CL3, as well as the lack of battery in chain IDI to II2 due to relay II5.

At the end of the conversation, the called party controls only relay IIB, irrespective of whether he hangs up first or last.

The calling party in hanging up, releases re lays 28 and 24, also II'I, II8 and |I5. The release of relay 23 removes the busy test from the code call lines and also releases relay 24. Relay I I'I removes ground from relay H8; which latter in turn opens the circuit of relay I I5 at armature |45, and relay IIS at armature 54.

Should the calling party abandon the call before the called party answers, thereby releasing relays II'I and II8, relay II4 will be operated from grounded armatures I4 or 32 of relays III or II2, to armature I5 of relay |I3, to Winding of relay I|4 to grounded battery. This will complete a circuit for relay II5, at armature |48 and front contact of relay II4, through armature |41 and normal contact of relay II8, which will operate on the cutoff ground from relay I at the end of a complete code, and release the selected chain relays IUI to |I2 of the group E, which in turn release relays II4 and II5 to restore the circuit to normal. The circuit is: grounded battery to winding of relay IIE, contact |43, conductor |42, armature I 41 and normal contact of relay II8, armature |46 and front contact of relay II4, conductor I4I, armature |40 and front contact of relay I, conductor 89 to ground.

Although a preferred embodiment of this invention is illustrated, and the preferred method of operation described, variations within the true spirit and scope of the same are to be determined by the appended claims.

Having thus described my invention, what I claim is new and desire to secure by United States Letters Patent is:

l. In an automatic telephone system, a codecall sending device, paths incoming thereto corresponding respectively to different telephone numbers, at least one of said telephone numbers having a plurality of suflixes, automatic switching equipment for extending connection to any one of said paths responsive to the dialing of the telephone number corresponding thereto, said code-call sending device being thereafter responsive to a dialed suffix of the telephone number, and means in said sending device for transmitting a code call of an identity depending both upon the path over which connection was made therewith and the suflix thereafter dialed.

2. In combination, a code-call sending device, paths incoming thereto, means for making connection therewith over any one of said paths, means subsequently controlled over any said path by which connection is made for imparting any one of a plurality of settings to the device, and means included in said device for sending out a code call of an identity depending both upon the path over which connection was made therewith'and the said setting imparted to the device.

3. In combination, a code-call sending device, means for effecting connection with said device responsive to the calling of any one of a group 5 is of a value depending upon the number called 10 to effect connection with the device, the other digit being of a value depending upon the setting subsequently imparted to the device.

4. In combination, a code-call sending device, paths incoming to said device, means for eiecting connection With said device over any one of said paths, means for directively setting said device over the effected connection, and means for thereafter operating said device to transmit a two-digit code call of which one of the digits is of a value depending upon the path used to effect connectin with the device, the other digit being of a value depending upon lthe setting subsequently imparted to the device.

5. In combination, a code-call line, a code-call sending device, paths over Which connection may be extended to said device, setting relays associated respectively with said paths, each of said relays adapted to be operated responsive to the making of connection with said device over the associated path, a recording device common to all said paths and arranged to be variably set over any path, and sending means controlled in accordance with Which of said setting relays is operated and in accordance with the setting of said recording device for sending out a code-call over said line.

BERT A. WALLACE. 

